Last spring, chemical engineering professors Tonya Kuhl and William Ristenpart
had the unique experience of having to
force students to leave a laboratory. “I just
want to try one more thing,” the students
would say. “We had to tell them, ‘It’s 15
minutes after we’re supposed to be out of
the space,’” explains Kuhl.

What got students so engaged? A course
developed by the University of California,
Davis professors: “The Design of Coffee.”
The class, first offered in spring of 2013 as a
freshman seminar and slated to expand to a
full-fledged course in January, will provide
an overview of chemical engineering as
seen through the lens of coffee brewing.

The expanded class will be offered in
two different versions: a general science
elective that will provide a nonmathematical introduction to how engineers
approach and solve problems and a version
for chemical engineering students that is
more “quantitative,” according to Ristenpart, with an additional lecture per week.

Although both courses are geared
toward freshmen (the version for chemical engineering students will be the
first required course in the major), the
general science class has enrolled
students in more than 50 disciplines from freshman to senior
level and even some engineering
graduate students. “We are pretty
sure they are coffee lovers and
want to take the course because
of their interest in coffee and the
hands-on laboratory experiences
and design that the course offers,”
says Kuhl.

In both classes, students learn
about chemical reactions, mass
transfer, fluid mechanics, and
optimization as they collaborate
in teams of three to brew the
best-tasting coffee using the least
amount of energy. A blind taste test
with a judging panel—along with a
calculation of energy expended to
create a liter of the coffee—results
in a ratio that crowns the winner
at the end of class.

Students have to makechoices such as which type ofbeans to use, how long to roast them (darkerroasts result in more of the typical coffeetaste but also require more energy), andhow much to heat the water (cooler watersaves on energy but then the flavor extrac-tion is “suboptimal,” says Ristenpart).

“It was amazing when we did thefreshman seminar trial run how diversethe coffees were,” he notes. “Some werelike battery acid. Some were delicious.There was quite a bit of variety based ondesign choices.”The freshman seminar launched with18 students. Now the general educationsection will comprise 300 with 60 onthe waiting list, and the chemical engi-neering section will include another 160after adding an extra section. The profes-sors say they’re working hard to keep upwith demand and they hope to eventuallyexpand the class to other departments anduniversities.

Kuhl says The Design of Coffee, which
engages students by allowing them to
problem solve under their own direction, is
the most enjoyable course she’s ever been
involved with. A student told her it was the
best class he’d ever taken.

But the course also has wider implications.

For chemical engineering majors, the
class can provide meaningful lab experience to keep them engaged and retained
before they’ve gained the training to handle
dangerous chemicals.

And Kuhl envisions first-generation
students better able to explain their major
to their parents back home through the
metaphor of coffee.

In addition, she explains that she and
Ristenpart hope to lure some of the general
education students into chemical engineering—or at least to better inform them
how engineers approach problems and
design processes. Ristenpart points out
that The Design of Coffee can give a wide
variety of students a better understanding of
the profession that goes beyond the image of
“smokestacks polluting the environment or
[engineers] adding toxic chemicals to food.”
Instead, he stresses, students can better
understand that the field is a “quantitative
way of thinking about the world around us
and how to design things in an optimal order.”

“Chemical engineers will take over
the world,” says Kuhl. “Via coffee,” adds
Ristenpart.

Engineering the Perfect Cup

STUDENTS IN THE DESIGN OF COFFEE CLASS MAKE DECISIONS ABOUT BEAN ROASTING TIME, WATER TEMPERATURE, BREWING
PROCESS, AND MORE TO CREATE THE IDEAL CUP OF COFFEE.